Lifting jack



C. E. BRANicK LIF'IIING JACK Dec. 14, 1954 Filed Dec. 18, 1952 INVENTOR.WQJ Z.

United States Patent LIFTING JACK Charles E. Branick, Fargo, N. Dak.

Application December 18, 1952, Serial No. 326,650

2 Claims. (Cl. 254-1) My invention relates to lifting jacks and, moreparticularly, to heavy-duty pressure-operated lifting jacks forautomotive vehicles and the like.

The primary object of my invention is the provision of a device of theclass described which has more lifting power per weight than anyportable lifting jack of the type heretofore produced.

A further object of my invention is the provision of a lifting jack ofthe class described which has a minimum of working parts, is extremelydurable, is readily portable, and which is extremely easy to positionbeneath an automotive vehicle and be removed from thereunder.

A still further object of my invention is the provision of a heavy-dutylifting jack for automotive vehicles which is provided with a cylinderwhich is mounted on the wheel-equipped carrying handle and in which theconnection between the handle and the cylinder is such that the cylinderalways remains in an upright vertical position.

A still further object of my invention is the provision of a device ofthe class immediately above described which draws its source of fluidunder pressure from a remote source, and in which the rearwardlyextended handle is provided with aconduit which leads from an inlet endadjacent the free end of the handle to the cylinder, thus facilitatinginsertion of air under pressure from an air hose while the piston ispositioned in an inaccessible place beneath the vehicle.

A still further object of my invention is the provision of a device ofthe class described wherein the lifting plunger is provided with novelmeans for varying the effective overall length thereof.

The above and still further objects of my invention will become apparentfromthe following detailed specification, appended claims and attacheddrawings.

Referring to the drawings wherein like characters indicate like partsthroughout the several views:

Fig. 1 is a view in side elevation of my novel structure;

Fig. 2 is a view in top plan of the structure of Fig. 1;

Fig. 3 is a vertical axial section taken substantially on the line 33"ofFig. 2;

Fig. 4 is a fragmentary view of a portion of Fig. 3 showing a differentposition of some of the parts; and

Fig. 5 is a view in perspective of the upwardly stepped bottom endportion of the lifting plunger.

Referring with greater particularity to the drawings, the numeral 1indicates in its entirety a cylinder, the ground-engaging base of whichis identified by the numeral 2 and the removable head by the numeral 3.Bolts 4 on the head 3 extend into the upper end of the cylinder wall 5of the cylinder 1. Mounted for vertical reciprocal movements within thecylinder 1 is a piston 6, which is provided with a sealing leather 7retained in place by a headed bolt 8 and a retaining washer 9. A liftingplunger 10 projects upwardly through an opening 11 in the head 3. Asuitable sealing, washer 12 is retained about the lifting plunger 10 bymeans of an annular retaining plate 13 held in place bycircumferentially-spaced bolts 14 therethrough, which have their screwthreaded ends in engagement with the head 3. As shown, the liftingplunger 10 is tubular and at its bottom has a core 15, which is retainedin place by the threaded bolt 8. The upper end portion of the core 15 isprovided with circumferentially and axially spaced steps 16. A plungerextension member 17 is telescopically received within the ice liftingplunger 10 and has reversely positioned circumferentially and axiallyspaced steps 18 thereon, which are adapted to cooperate with the steps16 of the core 15 to effectively vary the overall length of the liftingplunger 10, as shown by Figs. 3 and 4. The extreme upper end of theextension member 17 is preferably knurled, as at 17', to preventslippage of an axle or other portions of an automotive vehicle therefromduring lifting.

An elongated handle 19 has a bifurcated forward end portion, the forksof which are identified by the numeral 20. As shown, the cylinder 1 isreceived between the forks 20 and each of the forks 20 is pivotallysecured to opposite sides thereof above the center of gravity by meansof upstanding lugs 21, the pivot points being identified by the numerals22. The forward ends of the forks 20 project outwardly of the cylinder 1and are rigidly tied together by an axle 23 upon which are journalledspaced roller elements 24. As shown, the roller elements 24 engage theground only upon upward swinging movements of the handle 19 on the pivot22. In this manner, the relatively heavy cylinder 1 may be readilytransported, while the same is continuously retained in a verticalposition due to the pivot point 22 being above the center of gravity.The relatively long handle enables the operator to reach any desireddistance under a vehicle with ease, the effective length of the liftingplunger 10 being arrived at in advance by placing one or more of thesteps 18 of the extension member 17 in engagement with the correspondingsteps 16 on the core 15.

For the purpose of introducing fluid under pressure into the cylinder 1beneath the piston 6, I provide a flexible conduit 25, which enters aninlet port 26 into the bottom of the cylindrical wall of the cylinder 1and enters the handle 19, shown as being tubular in form. The conduit 25projects outwardly from the handle 19 adjacent its free end 27, asindicated at 28. An air hose from a source of fluid pressure, not shown,may be applied to the portion'28 to raise the piston 6 and the liftingplunger 10. Suitable valve mechanism of conventional type for retainingthe air within the cylinder 1 and for permitting same to escapetherefrom may be inserted in the portion 28 of the conduit 25.

My invention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the above objects, and while Ihave shown a commercial embodiment thereof, it is obvious that the sameis capable of modification without departure from the scope of theappended claims.

What I claim is:

l. A mobile jack for automotive vehicles comprising a verticallydisposed cylinder normally seated upon the ground, a piston mounted forreciprocal movements within said cylinder, a lifting plunger carried bysaid piston and projecting upwardly through a head on said cylinder, anelongated handle terminating in a bifurcated forward end portion, meanspivotally mounting each of said forward ends to an opposite side of saidcylinder above the center of gravity of the cylinder for relativeswinging movements thereof on a horizontal axis, the free ends of saidbifurcated portion projecting forwardly beyond said cylinder and beingprovided with roller elements, said roller elements being engageablewith the ground upon elevation of the other end of said handle aboutsaid pivotal connections with said cylinder, and means for actuatingsaid lifting plunger in said cylinder.

2. The structure defined in claim 1 in which said roller elements arejournalled to an axle spanning the free ends of said forks.

References Cited in the file of this patent UNITED STATES PATENTS

